perf(templates): resync and resolved-members read only the chain/subtree (ScadaBridge#89)

The last two whole-library template reads are gone. Both fed the
inheritance-only TemplateInheritanceResolver, which walks one template's
parent chain and never follows compositions.

- TemplateService.ResyncInheritedMembersAsync (operator repair, CLI + editor)
  now reads #86's GetTemplateReconcileClosureAsync (derived subtree + the
  template's chain, tracked). When nothing derives from the template the
  closure is empty, so it falls back to the new tracked
  GetTemplateChainAsync - resyncing a leaf reads only its own chain.
- ManagementActor.HandleGetResolvedTemplateMembers now reads
  GetTemplateChainAsync(id, trackChanges: false): the chain alone, untracked,
  with script bodies (the resolver projects script code, so #66's body-free
  analysis closure would not be equivalent).

The chain walk is factored out of TemplateReconcileClosure into
CollectChainAsync (one load per level, stops on parent cycles and dangling
parents) and shared by both.

Evidence:
- TemplateChainReadTests (#86 fixture): for every template plus an unknown
  id, the closure-backed resync issues exactly the writes, audit row and
  result of the whole-graph resync with GetAllTemplatesAsync wired to throw;
  the resolver answers identically from the chain and the whole graph.
  17 of these fail against the old service; 13 fail with the leaf chain
  fallback removed (mutation-checked).
- TemplateChainRepositoryTests (SQLite, recorded SQL): a 4-deep chain loads
  4 templates / 8 attributes instead of 46 / 92, one split-query set per
  level, untracked on request and tracked for the resync.
- ResolvedTemplateMembersReadTests: the actor answers from the untracked
  chain read and never calls GetAllTemplatesAsync (fails on the old actor).

Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV

docs/requirements/Component-TemplateEngine.md

@@ -233,8 +233,13 @@ template's derived subtree plus its own inheritance chain, tracked and fully inc
 one load per subtree depth and chain level (Gitea #86). The reconcile is
 inheritance-only, so every descendant's chain lies inside that set; a template with no
 children costs a single empty probe query. It still accepts an already-loaded tracked
-graph from a caller holding one. The operator `ResyncInheritedMembersAsync` and the
-flattener keep reading the whole tracked graph via `GetAllTemplatesAsync`.
+graph from a caller holding one. The operator `ResyncInheritedMembersAsync` reads the
+same reconcile closure and, when nothing derives from the template (empty closure),
+falls back to `GetTemplateChainAsync` — the template's own inheritance chain, tracked,
+one load per level — since resyncing a leaf reads only its chain (Gitea #89). The
+read-only resolved-members query (`GetResolvedTemplateMembersCommand`, behind the
+editor's inherited view and CLI `template resolved-members`) reads that chain alone,
+untracked. The flattener keeps reading the whole tracked graph via `GetAllTemplatesAsync`.
 
 ### Native Alarm Source Resolution